Threat of global warming sparks U.S. interest in geoengineering

President Obama has pledged to end America¿s dependence on foreign oil and his administration is spending billions on greener energy initiatives. Few issues are considered more urgent by the White House and average Americans than securing affordable and more environmentally friendly energy sources.

It's come to this: Climate-conscious policymakers are beginning to contemplate the possibility of playing God with the weather in the hope of slowing global warming.

For years it was considered downright wacky in official Washington to discuss geoengineering: altering the climate by reflecting sunlight back into the sky, sucking carbon dioxide from the air - or a host of other gee-whiz schemes. But in the past year the wacky has won a following, spurred in part by the recent collapse of climate legislation as well as by growing interest among private entrepreneurs and foreign officials.

House Science and Technology Committee Chairman Bart Gordon(D-Tenn.), whose panel will jointly release a report on climate engineering with the British House of Commons this month, said the subject is "just now starting to get some attention" even though people recognize the danger in trying to change a complex weather system.

"The more you know about it, the more you're concerned about if we can ever implement it," Gordon said in an interview. "However, there may be a point where we're up against the tipping point, and the consequences of climate change are even worse."

Over the next few months, whispering about changing the weather will evolve into written recommendations. Several key groups - including the Government Accountability Office and a bipartisantask force of experts - will issue their thoughts on how best to start a modest federal research program on geoengineering.

"We're getting a sense that agencies are interested in this topic and would be open, on a certain level, to letting this program go forward," said Jane Long, who co-chairs the National Commission on Energy Policy's task force.

At this point, though, even the experts most seriously looking at climate engineering describe it as a last resort for when climate impacts become a serious threat and the world has yet to wean itself off fossil fuels.

"Geoengineering only makes sense - if it makes sense, and that's an important conditional - as a way to bridge this crisis period," said Steven Hamburg, the Environmental Defense Fund's chief scientist.

Climate engineering can be divided into two basic categories, both of which are untested on a large scale: solar radiation management, which aims to deflect sunlight away from the Earth, and carbon dioxide removal, which takes already released greenhouse gases out of the atmosphere.

The first approach is relatively cheap and easy to deploy - researchers envision spraying small metallic particles or sulfur into the stratosphere, which could be accomplished with jets or even World War II-era howitzers - but this would do nothing to address the root causes of climate change or some of its worst effects, such as ocean acidification. The second method would address the atmospheric concentrations of carbon that can spur climate change, but it would take more time to develop and be much more expensive.

At this point, many scientists argue that it is worth scrutinizing different geoengineering techniques to see what could work and what will not. At a conference last week sponsored by Arizona State University, the New America Foundation and Slate magazine, University of Maryland distinguished professor of economics Thomas Schelling said "field experiments are going to be essential" to determine whether humans can manipulate the climate in a responsible and effective way.

"If solar radiation management is a bad idea, the sooner we discover that the better," said Schelling, who serves on the National Commission on Energy Policy task force.